Video technology relates to electronically capturing, processing, recording, and reconstructing a sequence of still images referred to as frames, so as to represent motion. Video includes a number of frames based on a predefined frame rate. For example, in the U.S., the Advanced Television Systems Committee (“ATSC”) establishes a standard frame rate of 29.97 frames/second for video used for commercial broadcasting.
For video transmitted via a digital video signal (e.g., based on the high definition serial digital interface (HD-SDI) standard), each frame is represented by a number of pixels commonly described as the smallest unit of an image that can be represented or controlled. The number of pixels in a frame is based on a predefined resolution of the frame (typically defined by a number of columns and rows of pixels). For example, a frame having a resolution of 1920 columns and 1080 rows is referred to as 1920×1080 and is represented by the arithmetic product of approximately 2,073,600 pixels. Pixels have many attributes, including for example, chrominance values that represent color, and luma values (referred to herein as lumas) that represent brightness. Once captured and processed, video is typically encoded and recorded as a digital file. Thereafter, the file is retrieved and the video is reconstructed by decoding the file.
A frame also has a signal aspect-ratio that defines the proportional relationship between the width and height of the frame. Since video includes a plurality of frames, video is also referred to as having a particular signal aspect-ratio (provided the signal aspect-ratio of its frames is uniform). In one example, a frame having a resolution of 1920×1080 has a signal aspect-ratio of 16:9 or ˜1.77:1. This ratio is defined in the HD-SDI standard. Standard definition signals typically have a signal aspect-ratio of 4:3 or approximately 1.3:1. In addition to having a signal aspect-ratio, frames also have a video aspect-ratio that defines the aspect-ratio of the video (sometimes referred to as the active video) in the frame. A difference in the signal and video aspect-ratios typically results in horizontal or vertical black bars being included in the frame to adjust for such differences. Such is often the case when video is converted from one format to another.
For example, consider video having a 4:3 video aspect-ratio that was originally recorded in a standard definition analog format with a 4:3 signal aspect-ratio, and was converted to a high definition digital format based on the HD-SDI standard with a 16:9 signal aspect-ratio. While the resulting frames would have a 16:9 signal aspect-ratio (since that it what the signal supports), the video aspect-ratio remains at 4:3. To make up the difference in these dimensions, vertical black bars are added to the left and right edges of the frames and around the content. Similarly, for video having a 16:9 video aspect-ratio that is initially recorded in a format with a 16:9 signal aspect-ratio, but which is then converted to a format with a 4:3 signal aspect-ratio, the resulting frames may have horizontal black bars on the upper and lower edges of the frames and around the content.
When watching video on a display device, users often desire to “correct” the presence of black bars by modifying a display setting on the display device. For example, the display device may provide an option to select a full, letterbox, horizontal stretch, or pan-and-scan zoom mode, whereby select portions of the video are enlarged or shifted to reduce or eliminate the presence of black bars. While portions of the video may be lost, often users are willing to accept such a loss to have the screen “filled.” However, while many users desire to modify such display settings, often users are unaware of their availability and/or do not take the time to modify them, particularly when they need to be changed repeatedly as the video changes (as, e.g., a user changes channels).